Lots of Republicans teed off against their own presumptive presidential nominee over the weekend after Donald Trump claimed that Judge Gonzalo Curiel had an inherent conflict of interest in overseeing the Trump University case because of his Mexican heritage. And now it turns out that even members of Trump’s own campaign staff are reportedly fed up with Trump’s constant race-baiting on the campaign trail.

“There’s growing internal dissent,” said NBC reporter Katy Tur on Morning Joe this morning. “Absolutely. And for the first time, I’m hearing inside the campaign, the same things that I’ve been hearing outside the campaign… I’m hearing aides say that this is extraordinarily frustrating to them, that they believe these are the sort of things that will end up sinking this campaign. The biggest hurdle right now is the candidate himself, because he says what he wants, no matter what they do behind the scenes.”

Trump has been race-baiting for months, of course, but it seems that some campaign staffers finally reached their breaking point when Trump went after Judge Curiel’s heritage in defending himself in the controversy over Trump University.

“The Judge Curiel comments, for a lot of people, are a bridge too far,” Tur explained. “Is it enough for them to quit and to find work elsewhere? No, not as of now. But they think at the same time they can hire all the people that they want, they can hire the best people if they could get them, but it doesn’t ultimately matter, because Donald Trump will say what he wants.”

So it sounds like a grown man who has the impulse control of a toddler can’t just magically become a disciplined politician with a consistent message. Who would have thought?